The present invention relates to a micro-leakage regulating valve which is capable of generating a reference leakage for calibrating a leakage measured by leakage test equipment.
Leakage test equipment is used to test containers which must be free from leakage of gas or liquid, or gas fittings. The test equipment applies a fixed pneumatic pressure to the device under test and a leak-free reference container of the same content volume as the device under test, monitors the difference in internal pressure between the device under test and the reference container, and measures the differential pressure to thereby make a check for leakage.
In such a leakage test equipment the sensitivity for detecting leakage is calibrated by:
(A) generating a known amount of leakage at the side of the device under test, or PA1 (B) changing the content volume of the device under test by a known value so that the resulting differential pressure produces the same effect as that by leakage.
With method (A), when the amount of leakage is relatively large, it can be set to a desired value by use of the existing throttle valve or the like. In the case where the amount of leakage is, for example, as small as 1 cc or less per minute, it cannot be set by the conventional means, and even if it can be set, the set state is unstable.
The method (B) is suitable for reproducing a very small amount of leakage, but this method calls for conversion between a volume change and the amount of leakage, and hence consumes much time for calibration. On this account, there is a strong demand for the implementation of a micro-leakage regulating valve which permits reproduction of a very small amount of leakage.